Certain applications require pumping of fluids. One common way of pumping such fluids is by using rotating blades which cut through the fluid and cause a flow. Other techniques for pumping fluids are known including peristaltic pumps, as well as an impedance pump as described in U.S. Pat. No. 6,679,687.
Certain kinds of fluids, such as blood or certain kinds of polymers, cannot be easily pumped using rotating blades. In the case of blood, the blades may harm some of the living cells within the fluid.